Door control mechanism



y 4, 1965 J. F. DYBEN 3,181,856

DOOR CONTROL MECHANISM Filed Dec. 13, 1962 2 Sheets-Sheet 1 214, I4 I88 4' ii F -I2 r IO FIG. I

INVENTOR.

JERRY F. DYBEN ,4,mq m

ATTORNEYS y 1955 J. F. DYBEN noon CONTROL MECHANISM 2 Sheets-Sheet 2 Filed Dec. 13, 1962 lNVENTOR-JERRY E DYBEN BY I 7%vm ATTORNEYS United States Patent 3,131,856 DOOR CONTRQL MECHANISM Jerry F. Dyben, South Bend, Ind, assignor to Communications Research, llnc., South Bend, Ind, a corporation of Indiana 7 Filed Dec. 13, 1962, Ser. No. 244,378 11 Claims. (Cl. 268-65) The present invention relates to a door control mechanism and more particularly to a door control mechanism which operates a door automatically in response to the presence of a person or object in front of the door.

With the advent of the supermarket and similar establishments handling a large number of people, automatically operated entrance and exit doors have virtually become essential, since those entering and leaving the establishments usually are carrying heavy loads of packages and the like or are pushing a cart loaded with purchases, and are often carrying or leading small children and/ or pets. In the past, as well as at the present time, these entrance and exit doors have been operated either by a light beam and a photo-electric cell or mats installed on both sides of the doors for controlling electrically operated door opening and closing mechanisms. Both types of these widely used door control and operating mechanisms have certain inherent disadvantages or characteristics which render them unsafe under certain conditions or which require excessive amounts of service and repair and frequent replacement. The photo-electric cell type Will operate satisfactorily under most conditions when adults or large children use the door in the normal manner; however, it will occasionally fail to function properly in response to various types of carts and objects, and small children and pets. Further, dead spots in the control mechanism are difiicult to eliminate, and hence the door may fail to function or cease to function at critical stages in the opening and holding operation, occasionally resulting in serious injury to the one passing through the door. Although the mat type door control overcomes most of the disadvantages and diiiiculties inherent in the photoelectric cell type, the mat type also has certain inherent disadvantages, including dead spots between mats on the entrance and exit sides of the door, frequent and expensive mat repair and replacement operations, and nonresponsiveness to objects approaching the door in advance of a person or vehicle without contacting the mat. Most of these difliculties may be overcome by specially designing the mats for various installations or including special features, and these special designs and features render the installation and service costs excessive or prohibitive. It is therefore one of the principal objects of the present invention to provide a door control and operating mechanism which is responsive to the presence of a person or object in a relatively large area on the entrance side of the door and without the person or object necessarily contacting the floor or other physical control member, and which will respond to the presence of relatively small bodies over a wide vertical range.

Another object of the invention is to provide a door control mechanism which can be easily installed, either temporarily or permanently, without reconstructing or damaging the floor or wall structure on either side of the door, and which after installation requires little or no service or other attention to maintain it in satisfactory operating condition.

Still another object of the invention is to provide an automatically operated door control mechanism which will operate safely and efiiciently under adverse operating conditions and in spite of careless and attempted improper use of the door.

A further object of the invention is to provide a con- 3,181,856 Patented May 4, 1965 trol mechanism of the aforesaid type which is relatively simple and compact and is constructed of standard components readily available on the market, and which can be readily adapted to a variety of different types of installations and uses without altering the basic design or mechanism.

Additional objects and advantages of the invention will become apparent from the following description and accompanying drawings, wherein:

FIGURE 1 is a diagrammatical view of a door and conrol mechanism embodying the present invention;

FIGURE 2 is a schematic diagram of a portion of the circuit of the present door control mechanism; and

FIGURE 3 is a schematic diagram of the basic circuit used in conjunction with the circuit of FIGURE 2 for controlling a door operating mechanism.

Referring more specifically to the drawings and to FIGURE 1 in particular, numeral 10 designates the door pivotally mounted on a pivot hinge 12 within door frame members 14 and 16, the door being so mounted by hinge 12 that it swings toward the left from the fully closed position shown in full lines to the fully opened position shown in broken lines. The floor 18 forms the approach to the door, and the floor 20 forms the exit from the door. The two floor portions 18 and 20 are separated by a sill 22, the two floor portions and sill being solid, non-movable members of conventional construction. Positioned vertically along each side of the door at the entrance are railing structures 24 and 26, and positioned along the exit are railing structures 28 and 30, the four railing structures being positioned vertically and disposed in close proximity to the opposite edges of the door opening; however, in the drawings, the railing structures are shown lying horizontally on a plane with the floor in order to better show and illustrate in a single view the relationship and operation of the parts forming the present control mechanism installed adjacent the door.

Mounted on railing structures 26 and 30 on the entrance and exit sides of the door, respectively, are transmitter antennas 32 and 34, and mounted on railing structure 24 is receiving antenna 36, and on railing structure 28 are receiving antennas 38 and 40. The transmitter and receiving antennas when in operation form capacitors and create an electrical field between the railing structures on opposite sides of the entrance and exit sides of the door for sensing the presence of a person or object approaching or passing through the door. The signal thus created is transmitted to a control mechanism for operating the door in response thereto, as will be more fully described hereinafter. This type of door installation is designed primarily for use in conjunction with super markets and similar establishments, and a multiple installation would normally be used, one for the entrance of the customers into the establishment and the other for the exit of the customers, the two installations being placed side-by-side and the railing structures 26 and 30 being adapted to support two antennas for the adjacent doors. The particular type of door design and railing structure are used herein merely for the purpose of illustrating the invention and do not form a limitation thereon.

The transmitter circuit is shown in'the schematic dia gram of FIGURE 2 and is connected to antennas 32 and 34- by leads 32' and 34, respectively. In this circuit, a positive buss 41 is connected through a resistor 42 to the antennas and to the collector of an NPN transistor 44. The emitter of transistor 44 is connected to a negative buss 46, and the base voltage of transistor 44 is set from buss 4a through a resistor 43. The base voltage on transistor 4 is forward biased cyclically by the circuit including a unijunction 52. Terminal 54 of unijunction 52 is connected to a positive buss $6 through a resistor 58, while terminal 6t is connected to buss 46 through capacitor s2 and variable capacitor 64, connected in parallel, and to buss as through a resistor 66. The values of these components are chosen to render transistor 44- slightly conducting by maintaining a reverse bias on the base of the transistor through resistor 48 except for a "short period in every cycle when the action of unijunction 52 connects buss 56 with the base of transistor 44 to forward bias the base and allow current to flow from buss 41 to buss 46. Throughout the remainder of this description, the values of the components are assumed to be such as to allow current to flow from buss 41 to buss 46 for microseconds out of every 50 microseconds, giving'a frequency of 10,000 cycles per second; however, this rate is readily varied by varying capacitor 64. If desired, a more powerful oscillator circuit may be utilized in place of the one including transistor 44. I

Referring to primary control circuit 68 in FIGURE 3, antenna 36 for sensing the presence of a person or object approaching door It is connected to the base of an NPN transistor 7!) through lead 71 and a resonating circuit consisting of a coil 72, and variable capacitor '74, and through a variable resistor '76 and resistor 78 in series to buss 46. Resistor '76 is varied to vary the amount of energy reaching the base of transistor 7t), as will be described later. A slight forward bias is maintained on the base of transistor 79 by resistor 82. Capacitor 80 is a filter capacitor to reduce undesirable high frequency signals. Resistor 78 provides a slight amount of degeneration for more stable operation. The values of the components are chosen in such a manner that transistor 7d acts as a class C amplifier, and the resonating circuit containing components 72 and 74 is tuned to kc.

The collector of transistor '70 is connected to a PNP transistor 99 through a circuit consisting of a capacitor 92, coil 94, and resistors96 and 97 connected, in series in the order named, between the base and emitter of the transistor, with the collector of transistor '70 being connected between capacitor 92. and coil 94. The coil is wound in such a manner that it is a parallel resonant circuit at 10 kc. The base of transistor 9t) is also connected to its collector through a resistor 98, and the emitter is connected to a positive buss 100 through a resistor 101.

Feedthrough capacitors Hi2 and 104 are provided for buss 1% to prevent high frequency signals which may appear on buss 10:! from reaching the transistors. Transistors 7t) and 94 form two stages of an amplifier, which may be modified by changing the number of stages or the power or by any other desired modification without departing from the present invention.

7 The collector of transistor 90 is connected through a resonating circuit consisting of a capacitor 105, a coil 1%, Wound in the same manner as coil 94, and a resistor 18%, in series in the order named, between the base and emitter of a transistor lit with a zener diode 112 connected between the capacitor and the base, and with the collector of transistor 76 connected between the capacitor and the coil. Although this resonating circuit acts to amplify the signal coming from the transistor 99 in much the same manner as the circuit between transistors 7th and 90, a diode 113 having one end connected between capacitor 1% and zener diode 13.2, and its other terminal connected to the emitter of transistor 110 acts to pass only the positive portions of the waves coming from transistor Furthermore, zener diode 112 cuts oif from transistor lid all but the higher positive values of the remaining portions of the waves. Thus, only a pulsing D.C. current whose peak voltage depends on the value of field between antennas 32 and 36 reaches the base of transistor 31w. Resistor 116 stabilizes the operation between the emitter of transistor iii and buss as.

The collector of transistor till is connected through a circuit consisting of a capacitor iii; and coil 119 to a PNP transistor 1125 with the capacitor and coil in series between the base and the emitter of transistor 12%. The emitter of transistor 12:) is connected to buss 1th) through make transistor 148 conduct more.

a'resistor 132. The collector of transistor no is connected between coil 1119 and capacitor 113. The positive going signal on the base of transistor 11b is amplified and inverted 180 so that a negative going pulse is producod across coil 119 and coupled to the base of transistor 12%) through capacitor 118. The negative going signal on the base of transistor T20 produces a positive going signal across thermistor 133 and resistor The collector of transistor 1% is connected through zener diodes 14a and 1 32 to the base of transistor 14%. The amplified signal of the collector of transistor 144 is connected to the base of transistor 14% and the collector of transistor 148 is connected to relay 15%, the emitters of transistors 144 and 148 being connected to negative buss as. A circuit 151, including capacitor 152 and thermistor 15 has been included in the circuit to eliminate the effect of temperature changes on transistor 144.

The resistor 156 and zener diodes 15S and res, connected between transistors 12th and 14-4 and buss 46 provide a stabilized minimum bias, and a zener diode 162 and resistor 154- between transistors 17-9 and 144 are connected to the base of transistor M3 to act as a level diiterence sensing circuit.

The pulses from transistor 124 are developed across thermistor 133 and resistor 1'34, and zener diode Mil passes only the most positive portion of the wave form. Capacitor 152 and thermistor 154 form the main body for the filtering of the DC. pulses to some steady state D.C. value. The value of this energy depends upon whether a person is in the held or whether an increase in signal is accomplished by an object or body such as a basket being struck across the field and allowing an increase in signal. Zener diodes 158 and res and resistor 156 form a circuit of holding the D.C. level to some reference value. Zener diode 152 is a higher value zener and the'energy levelin the condition with no person in the door'is high enough to keep transistor 148 conducting, and therefore relay Ildti in an energized state. Zenery action of diode 142 is higher than that of zener diode 162, and functions to increase the si-gnal strength, raising the D.C. leveland allowing zencr diode 152 to conduct harder, and would try to However, zener diode 142 would make transistor T44 conduct, which would back bias transistor 148, thus causing the relay to deenergize. This condition is necessary in thatthe energy estab lished in the field between antennas 32 and 36 will normally be absorbed by a body, but in case a metallic basket ing antenna, causing an increase in the signal rather than the normal decrease required to activate the door.

This

7 increase in'signal would be detrimental to operation of the door since'it would normally keep transistor 14% conducting and therefore relay 1% energized. The circuit function of diode 142 in response to the signal increase causes transistor 14% to conduct, and through transistor 148 back biases transistor 5M3, causing the condition of cutoff for transistor 148, thus dcenergizing relay i), and providing a voltage level between two extremes.

Relay '15s operates two sets of contacts indicated by numerals 17d and 172. Contacts 17% control circuit 174 controlling the operation of the power mechanism for opening and closing the door. This type of mechanism is.

Well known and readily available on the market and hence will not be described herein. Contacts 172 control the circuit of reed relay 1%, which in turn controls contacts 182 in lead '71 and contacts 184- in a holding circuit consisting of antenna 38, lead 136 and mechanically operated switch 1-38, switch 1% being closed by the door when it reaches substantially fully opened position. The reed relay 18$ alternates on negative half 60 cycles between contacts 132 and 184, with the combined energy level in the two circuits, identified by leads '7]. and res, not being suflicient to operate relay 15b to open contacts 17%?- and thereby close the door while a person or object is in the electrical field between the respective transmitting and receiving antennas. It is seen that antenna 38, which controls the circuit including lead 186, is substantially larger than antennas 36 and 40 since it must receive its signal through door when it is in opened position.

The safety control circuit identified generally by numeral 200 is basically the same as the main control circuit previously described; consequently, identical components and subcircuits will be designated by the same numerals with primes in the safety control circuit to identify respective components and subcircuits and will not be described in detail herein. The primary safety circuit consists of antenna 34 of the transmitter and receiving antenna 40, the latter antenna being connected by lead 202 with the safety control circuit previously mentioned controlling solenoid relay 204 including contacts 206 of the safety circuit. One contact of the relay is connected with a source or" electrical energy and the other contact is connected by lead 208 to the input line of relay 150 between transistor 148 and the relay. A delayed action circuit 210 consisting of a diode 212 and capacitor 214 prevents chattering of relay 150 when the safety circuit is initially operated. An oVer control switch 216 is actuated by the door and, as the door is opened, the switch closes, thus maintaining relay 204 in its energized condition and thereby contacts 206 in their opened position to prevent the safety circuit from interfering with the operation of the door after a person has started therethrough.

In the operation of the present door control mechanism initially with no person or object between antennas 32 and 36, the energy level between the two antennas is sufficient to energize relay 150 and thus maintain switch 170 of the door operating circuit open and the door closed, as shown in FIGURE 1. Likewise, the energy level between antennas 34 and 40 is sufiicient to energize relay 2% and thus maintain contacts 206 open and the safety circuit inoperable. Receiver antenna 36 is coupled to the input of the open E.S.-P. system through contacts 182 of relay 186 to the potentiometer 76, the potentiometer energy level is adjusted so that relay 150 is normally energized, and contacts 170 and 172 are normally opened when relay 150 is energized. When a person enters the electric field between antennas 32 and 36, the electric field energy therebetween drops as a result of the ground absorbing effect of the persons body. When enough energy from the electric field has been absorbed, relay 150 deenergizes and contacts 170 and 172 close, contacts 176 energizing the door opening mechanism and contacts 172 applying 60 cycles current to relay 1 80. The circuit of relay 189 permits only the negative portion of the 117 volt 60 cycle AJC. to energize the relay. When relay 135) is energized, receiver antenna 36 is removed from the circuit and receiver antenna 38 is connected to the input of the opened E.S.'P. system through micro-switch 183 which is closed when the door is fully opened. The energy now received by the opened E.S.P. system is chopped so that half its energy is received from antenna 36 and half from antenna '38. The chopped energy now received by the opened ESP. system is such that when a person is standing in receiver 36 field or between fields 36 and 3-8 or in field 38, the composite energy will not be large enough to energize relay 150. Only when no person or object is in the field will be the two composite field energies be equal and sufficient to energize relay 150. When this condition is met, the contacts 179 and 172 open and allow the door to close.

If a person should attempt to pass in the wrong direction through the door, the energy level between antennas 34 and 40 would drop and relay 2% would be deenergized, thus closing contacts 2%, which completes the safety circuit to relay 156, and this prevents deenergization of the latter relay and hence prevents closing of contacts 174? and 172, if a person should enter the field between antennas 32 and 36 while the person is still on the wrong side of the closed door, i.e. in the field between antennas 34 and 40. In normal operation of the door, the safety circuit is deenergized as the door opens by the opening of switch 216 as the door opens; i.e. as the door is opened it energizes relay 2.04, opening contacts 206 and thus disabling the safety circuit After the person has passed through the door and beyond railings 28 and 30, the energy level between transmitter and receiving antennas rises sufliciently to energize relay 150, thus opening contacts and 172 and permitting the door operating mechanism to close the door.

While the present mechanism has been described with reference to a door control mechanism, the mechanism can be readily adapted to various other types of operations with minor modifications, and the reference to the door control mechanism is intended primarily as a means of illustrating one embodiment and use of the present invention and, when used in the claims, is intended to include other sim ilar applications and installations.

I claim:

1. For use with a door having an entrance side and an exit side and being mounted to swing away from the entrance side: a control mechanism comprising a transmitter and receiver antenna on opposite sides of the entrance of the door, a transmitter and receiver antenna on opposite sides of the exit of the door, the receiver antenna on the exit side of the door being larger than the receiver antenna on the entrance side thereof, a circuit for said transmitter antennas for creating an electrical field between the respective transmitter and receiver antennas, a circuit for opening and closing the door, a relay having contacts for controlling the last mentioned circuit, said relay being energized to open said contacts, an amplifier circuit responsive to the electrical field between the antennas on the entrance side of the door for energizing said relay, a holding circuit for said relay having a reed relay for operating said first mentioned relay on one-half of the combined energy from the electrical fields between the respective transmitter and receiver antennas at the entrance and exit of the door, said first mentioned relay having contacts for controlling said holding circuit whereby said holding circuit is deenergized when said relay is energized, said holding circuit having a switch closed when said door approaches fully opened position, a safety circuit connected to and controlling said first mentioned relay, a relay for controlling said safety circuit having contacts for controlling said safety circuit, said relay being energized to open said safety contacts, a second receiver antenna on the exit side of the door adjacent said first mentioned antenna on the exit side of the door, an amplifier circuit responsive to the full electrical field between the transmitter antenna on the exit side of the door and said last mentioned receiver antenna for energizing said safety relay, and an overcontrol switch for said safety relay closed by opening of the door for rendering said safety circuit inoperative.

2.. For use with a door having an entrance side and an exit side and being mounted to swing away from the entrance side: a control mechanism comprising a transmitter and receiver antenna on opposite sides of the entrance of the door, a transmitter and receiver antenna on opposite sides of the exit of the door, the receiver antenna on the exit side of the door being larger than the receiver antenna on the entrance side thereof, a circuit for said transmitter antennas for creating an electrical field between the respective transmitter and receiver antennas, a circuit for opening and closing the door, a relay having contacts for controlling the last mentioned circuit, said relay being energized to open said contacts, an amplifier circuit responsive to the electrical field between the antennas on the entrance side of the door for energizing said relay, a holding circuit for said relay having a reed relay for operating said first mentioned relay ion one-half of the combined energy from the electrical fields between the respective transmitter and receiver antennas at the entrance and exit of the door, said first 8. In a control mechanism for use with a door having an entrance side and an exit side and being mounted to swing away from the entrance side: a transmitter and receiver antenna on opposite sides of the entrance of the door, a transmitter and receiver antenna on opposite sides of the exit of the door, a circuit for said transmitter antennas for creating an electrical field between the respective transmitter and receiver antennas, a circuit for opening and closing the door, a relay having contacts for controlling the last mentioned circuit, a circuit responsive to the electrical field between the antennas on the entrance side of the door for energizing said relay, and a holding circuit for said relay having a reed relay for operating said first mentioned relay on one-half of the combined energy from the electrical fields between the respective transmitter and receiver antennas at the entrance and exit of the door, said first mentioned relay having contacts for controlling said holding circuit whereby said holding circuit is denergized when said relay is energized, said holding circuit having a switch closed when said door approaches fully opened position, a safety cr-icuit connected to and controlling said first mentioned relay, and means for rendering said safety circuit inoperative when the door is opened.

9. In a control mechanism for use with a door having an entrance side and an exit side and being mounted to swing away from the entrance side: a transmitter and receiver antenna on opposite sides of the entrance of the door, a transmitter and receiver antenna on opposite sides of the exit of the door, a circuit for said transmitter antennas for creating an electrical field between the respective transmitter and receiver antennas, a circuit for opening and closing the door, a relay having contacts for controlling the last mentioned circuit, a circuit responsive to the electrical field between the antennas on the entrance side of the door for energizing said relay, a holding circuit for said relay having a reed relay for operating said first mentioned relay on one-half of the combined energy from the electrical fields between the respective transmitter and receiver antennas at the entrance and exit of the door, a safety circuit connected to and controlling said first mentioned relay, and means for rendering said safety circuit inoperative when the door is opened.

10. In a control mechanism for use with a door having an entrance side and an exit side and being mounted to swing away from the entrance side: a transmitter and receiver antenna on opposite sides of the entrance of the door, a transmitter and receiver antenna on opposite sides of the exit of the door, a circuit for said transmitter antennas for creating an electrical field between the respective transmitter and receiver antennas, a circuit for opening and closing the door, a relay having contacts for controlling the last mentioned circuit, a circuit responsive to the electrical field between the antennas on the entrance side of the door for energizing said rela and a holding circuit for said relay having a reed relay for operating said first mentioned relay on one-half of the combined energy from the electrical fields between the reseective transmitter and receiver antennas at the entrance and exit of the door.

11. In a control mechanism for use with a door having an entrance side and an exit side and being mounted to swing away from the entrance side: a transmitter and receiver antenna on opposite sides of the entrance of the door, a transmitter and receiver antenna on opposite sides of the exit of the door, a circuit for said transmitter antennas for creating an electrical field between the respective transmitter and receiver antennas, a circuit for opening and closing the door, a relay having contacts tor controlling the last mentioned circuit, a circuit responsive to the electrical field between the antennas on the entrance side of the door for energizing said relay and including means for operating said relay when the electrical field either decreases below or increases above predetermined values, and a holding circuit for said relay having a reed relay for operating said first mentioned relay on one-half of the combined energy from the electrical fields between the respective transmitter and receiver antennas at the entrance and exit of the door.

References Cited by the Examiner UNITED STATES PATENTS 2,631,226 2/36 Parvin 2681 3,050,661 8/62 Jenkins 3l7147 CHARLES E. OCONNELL, Primary Examiner. HARRISON R. MOSELEY, Examiner. 

10. IN A CONTROL MECHANISM FOR USE WITH A DOOR HAVING AN ENTRANCE SIDE AND AN EXIT SIDE AND BEING MOUNTED TO SWING AWAY FROM THE ENTRANCE SIDE: A TRANSMITTER AND RECEIVER ANTENNA ON OPPOSITE SIDES OF THE ENTRANCE OF THE DOOR, A TRANSMITTER AND RECEIVER ANTENNA ON OPPOSITE SIDES OF THE EXIT OF THE DOOR, A CIRCUIT FOR SAID TRANSMITTER ANTENNAS FOR CREATING AN ELECTRICAL FIELD BETWEEN THE RESPECTIVE TRANSMITTER AND RECEIVER ANTENNAS, A CIRCUIT FOR OPENING AND CLOSING THE DOOR, A RELAY HAVING CONTACTS FOR CONTROLLING THE LAST MENTIONED CIRCUIT, A CIRCUIT RESPONSIVE TO THE ELECTRICAL FIELD BETWEEN THE ANTENNAS ON THE ENTRANCE SIDE OF THE DOOR FOR ENERGIZING SAID RELAY, AND A HOLDING CIRCUIT FOR SAID RELAY HAVING A REED RELAY FOR OPERATING SAID FIRST MENTIONED RELAY ON ONE-HALF OF THE COMBINED ENERGY FROM THE ELECTRICAL FIELDS BETWEEN THE RESPECTIVE TRANSMITTER AND RECEIVER ANTENNAS AT THE ENTRANCE AND EXIT OF THE DOOR. 